This invention relates to the preparation for storage of fission products.
The safe storage of waste fission products presents a problem as the waste in many cases has to be stored over hundreds of years until its radioactivity falls to a level where it is no longer dangerous.
One solution to the problem, adopted at present, is to store the waste fission products in the form of liquids, and these liquids are stored in suitable containers or tanks where the fission products decay. Though the storage tanks may last for many decades depending on the materials of construction used to resist chemical attack, storage in liquid form does present problems in that the storage space required is large and the storage tanks have to be regularly inspected and eventually renewed.
Another solution to the problem which has been proposed is to form the waste fission products into glass bricks. This considerably reduces the required storage space, but the glass bricks would need to be enclosed in, for example, stainless steel containers to prevent any chemical or mechanical attack on the bricks.
The potential hazards that need to be considered when designing storage means for storing waste fission products include heat generated by the decay of the fission products or from some external source, mechanical damage to the storage means, chemical attack from the waste fission products and from an external source such as oxidation and corrosion, and diffusion of the waste fission products through the storage means. The waste fission products should also be in a convenient physical form so as to ease their subsequent mechanical handling. It is an object of the invention to provide an alternative method of preparing waste fission products for storage having advantages over the two methods described above.